The body, heated to a temperature of 100 ° C, was lowered into a calorimeter containing 200 g of water.

The body, heated to a temperature of 100 ° C, was lowered into a calorimeter containing 200 g of water. The initial temperature of the calorimeter with water is 23 ° C. After the establishment of thermal equilibrium, the temperature of the body and water became equal to 30 ° C. Determine the mass of the body if the specific heat of the substance from which the body is made is 187 J / (kg * K). Disregard the heat capacity of the calorimeter.

To find the mass of the body, lowered into the calorimeter, we use the equality: St * m1 * (tt – tp) = Sv * m2 * (tp – tv), whence we express: m1 = Sv * m2 * (tp – tv) / (St * (tт – tр)).

Variables and constants: Sv – specific heat capacity of water (Sv = 4200 J / (kg * K)); m2 is the mass of water in the calorimeter (m2 = 200 g = 0.2 kg); tр – equilibrium temperature (tр = 30 ºС); tv – initial water temperature (tv = 23 ºС); St – specific heat capacity of the body substance (St = 187 J / (kg * K)); tт – initial body temperature (tт = 100 ºС).

Calculation: m1 = Sv * m2 * (tp – tv) / (St * (tt – tp)) = 4200 * 0.2 * (30 – 23) / (187 * (100 – 30)) = 0.449 kg.

Answer: A body weighing 0.449 kg was lowered into the calorimeter.